creating array of fix and changing variables for xlswrite export

Hello All, I am in need of exporting my calculations to an excel spreadsheet. As shown in here: https://in.mathworks.com/matlabcentral/answers/101309-how-do-i-use-xlswrite-to-add-row-and-column-labels-to-my-matlab-matrix-when-i-write-it-to-excel-in-m

I have created 2 commands:

col_header={'Col1','Col2','Col3','Col4','Col5'};
data{ii}=[X1,X2,X3,X4,X5];
data_cells{ii}=num2cell(data{ii});

The variables X1,X2,X3,X4,X5 changes over the loop and I want to export each loop values for the same.

My main intent is to get a output file of excel spreadsheet with 5 columns named as:

col_header={'Col1','Col2','Col3','Col4','Col5'};

and the values of X1,X2,X3,X4,X5 will be pasted over the loop below the above titles respectively.

I tried this:

output_matrix=[{' '} col_header; data_cells];

But getting error of dimensions.

    Dimensions of matrices being concatenated are not consistent.

Please help me.

[alice]

I guess you want to use the code provided in https://in.mathworks.com/matlabcentral/answers/101309-how-do-i-use-xlswrite-to-add-row-and-column-labels-to-my-matlab-matrix-when-i-write-it-to-excel-in-m.

You can store your data in an array rather than a cell. Before the loop, you can preallocate data if you know the number of steps of your loop:

data = zeros(numberSteps,5);

During the loop, you write in this array:

data(ii,:)=[X1,X2,X3,X4,X5];

Then, after the loop, you can get a cell from this array this way:

data_cells = num2cell(data);

You have what you wanted, and you can add your headers and write to the excel file the same way as in the link:

output_matrix=[col_header; data_cells];
xlswrite('My_file.xls',output_matrix);

[adi kul]

Hi, Thanks for your help. I am getting

Subscripted assignment dimension mismatch.

error on this line of code:

data(ii,:)=[X1,X2,X3,X4,X5];

[alice]

What are the sizes of data, X1, X2, X3, X4 and X5 ? What is the value of your index ii when you get this error?

[adi kul]

ii is over a length of X1. Which I am giving as text input.

Now for ii=1:length(X1) the X3,X4 & X5 are calculated while X1 and X2 are 2 inputs.

Now I want to provide a solution result file where the X3,X4 and X5 are documented along with respective X1 and X2.

So suppose for 2 values of X1 and X2, the "data" will be 2x5 array.

I hope it helps.

Edit: I am getting this error when ii=1

[alice]

So your X1 and X2 are vectors with, let's say n elements.

• Are X3, X4 and X5 also vectors with n elements? Then you don't need a loop and you can directly use:

data=[X1,X2,X3,X4,X5];

• Or are they a number that changes in the loop? Then you keep the loop but in each line you just put the current element of X1 and X2:

data(ii,:)=[X1(ii),X2(ii),X3,X4,X5];

[adi kul]

X1,X2 changes over loop. And results of X3,X4,X5 are also changes as per X1 and X2.

All X1,X2,X3,X4,X5 are single numeric values.

I tried this:

data(ii,:)=[X1(ii),X2(ii),X3,X4,X5];

Still this error:

Subscripted assignment dimension mismatch.

[alice]

Can you tell what Matlab returns when you ask for the sizes of all items after you get the error (using the size function) please ? It would help understand.

nd = size(data(ii,:))
n1 = size(X1)
n2 = size(X2)
...
n5 = size(X5)

Answer 1

[dpb]

>> [{' '} col_header]
ans = 
  ' '    'Col1'    'Col2'    'Col3'    'Col4'    'Col5'
>>

You've added a blank column to the first row that isn't in the second; hence you can't (vertically) concatenate the two. Just lose the blank entry and set the target row/column in the spreadsheet to 'B1' instead of 'A1' if that's the intent.

However, you don't really need to do the concatenation, write

output_matrix={'Col1','Col2','Col3','Col4','Col5'};
...
for ii=iLo:iHi  % begin the loop
  ....
  % compute the values here
  ...
  output_matrix{ii+1}=num2cell([X1,X2,X3,X4,X5]);
  ...
end

Stylistic Comment: In general, having sequentially-named variables such as your X n above is indicative that haven't used the power of Matlab as fully as could have done. An array X may be much easier to code and maintain code for instead. We haven't seen the rest of the code that generated these names so can't give specifics, but it's worth looking at ways to vectorize the code and remove such repetition.